Responding to Climate Change in New York City

By Allan Frei and William Solecki | September 13, 2018

With global climate change upon us, New York City is already feeling
the effects. Rainfall patterns are changing, with more frequent severe
storms; the annual mean temperature has risen 3°F in our region since
the turn of the 20th century; and coastal areas are becoming
increasingly vulnerable to sea level rise. New York, like all cities, will
need to be resilient in the face of these new environmental stresses.

Resilience can be defined as the capacity to
recover quickly from disturbances, and it
requires both thought and vigilance. In
contrast, resistance refers to the ability to
remain unaffected by undesirable events.
Resistance to the potential impacts of climate
change on our city would be nice, but it is
unrealistic, and so we must strive for resilience.

The city’s long history of responses to
environmental challenges demonstrates its
capacity for resilience. During long periods
with no obvious threat, inertia can set in, but at
critical junctures decision makers have managed
to employ innovative solutions. Access to clean
drinking water and safe disposal of wastewater
have been ongoing challenges, and a brief
look at two historical examples provides some
insight into what resilience in the face of
climate change might look like.

During the early years of settlement,
the small population at the southern tip
of Manhattan drew water from local wells
but also dumped sewage and other waste
locally, contaminating the environment and
eventually their own water supply. There
wasn’t enough water to satisfy personal and
commercial use and municipal needs such as
water for firefighting.

In response to a series of devastating
fires and deadly epidemics in the early 19th
century, New York made a major paradigm shift
by following the examples of Philadelphia and
Cincinnati in developing a centralized water
supply system. Unlike those cities, whose
sources were local, New York built reservoirs
and piped in water from distant pristine
environments.

These efforts resulted in the completion
of the Croton Water Supply System in 1842,
providing a steady flow of clean water
to downtown Manhattan from northern
Westchester County. This groundbreaking
engineering achievement inspired other
growing eastern cities, such as Boston, to
centralize and expand their water supply
infrastructure during the population boom of
the mid-19th century.

More than a century later, a series of
droughts, along with changes to federal
regulations, brought a second major shift in
the way the city accesses and disposes of
water. During the 1980s and 1990s, these
droughts coincided with increased water use
so that during dry years, natural replenishment
of the reservoirs could no longer meet
demand. With no realistic prospects to further
expand the reservoir system, which had
already grown to include the Catskill/Delaware
Watershed, conservation and water pricing
suddenly, and for the first time, became a
central and successful element of New York
City’s water management program.

Average annual consumption fell by around 30 percent.
Around the same time, the city responded
to Safe Drinking Water Act amendments by
limiting economic development in watershed
areas in order to protect water quality.
After a series of lawsuits and negotiations,
the city worked out an arrangement with
communities upstate in which the watershed
would essentially be managed as a large green
infrastructure project. Rather than building
expensive engineering projects like treatment
plants, rules were put in place to protect the
natural ecological function of forests around
the reservoirs to ensure water quality. This
agreement also included a more equitable
relationship between watershed residents
and the city.

Moving forward, New York City will
need to respond on at least as grand a scale
to environmental challenges brought by
climate change. Increasing temperatures
will further affect our regional hydrology in
far-reaching ways. Altered seasonal patterns
of evaporation, snow melt, spring runoff,
and biological processes in the streams and
reservoirs are just a few likely consequences.
We don’t know exactly how aspects
of climate change will play out yet, but we
do know that very real changes to our local
environment are on the way, and that they
will require major changes in how we think
about our infrastructure. For example, more
frequent deluges in the city can flood our
storm drains and force sewage into the
surrounding waterways, a phenomenon
known as combined sewer overflow (CSO).

The city has already embarked upon a
green infrastructure campaign to enhance
local ecosystem services to mitigate the worst
CSO impacts. Projects include green roofs,
bioswales, and rain gardens. Former NYC
mayor Mike Bloomberg’s PlaNYC and Mayor
Bill de Blasio’s OneNYC provide blueprints for
continuing these resiliency efforts.
BBG’s Water Conservation Project
complements these efforts and provides
a model for the public to see how green
infrastructure can help manage excess rain.
During storms, the Garden grounds absorb
rain, allowing water to seep into the stormwater
system more slowly and diminishing
the magnitude and duration of CSOs.

A rock and soil weir filters
water and regulates pond depth. An
automated system triggers the pond to drain
in advance of wet weather so that it can hold
extra rainwater and minimize peak flooding.
This has already reduced BBG’s annual
wet-weather burden on the city’s stormwater
system from 8 million gallons to only 2ó million gallons.

When the project is completed this year, an underground pump
system will recirculate water back uphill to the
Japanese Hill-and-Pond Garden. The Garden’s
freshwater consumption for outdoor features
will ultimately drop from 22 million gallons a
year to less than 1 million.
These sorts of projects provide a
wonderful opportunity to promote the
understanding of sustainable water practices.
In the face of uncertainty about how climate
change will affect us locally, it is becoming
ever more crucial to appreciate resilience
and promote practices that will serve us for
decades to come. Cities across the world have
assumed leadership roles in these efforts, with
New York City at the forefront. It’s exciting
to see Brooklyn Botanic Garden part of that
transformative effort.

What Can You Do to Help Right Now?

You may have heard some of this advice before,
or it may be new to you. Either way, consider
putting these strategies into practice now.

Use Less Water in the First Place

Install WaterSense–labeled fixtures like
shower heads, faucets, and toilets. These meet
the EPA’s specifications for water efficiency.
WaterSense appliances are also available.

Find leaks and fix them.

Plant drought-tolerant species in your garden.

Reduce Your Contribution to Sewer Overflows

During a storm, hold off on doing laundry or
dishes or showering so that you don’t add
wastewater to the deluge. Waiting even just a
few minutes until the initial surge has passed
can make a difference.

Be a gardener. Any garden, even a container
garden, will help absorb excess rainwater and
reduce runoff.

Obtain a rain barrel to collect rain and use it
to water your plants.

If there is a city bioswale (curbside rain
garden or specially designed tree bed) near
your home, keep it clear of litter, and stay
tuned for city-led workshops for other
stewardship efforts.

Learn More

The Stormwater Infrastructure Matters
coalition (SWIM, swimmablenyc.org)
provides information and activities
to promote sustainable storm-water
management around New York City.

Calculate your water footprint using
the calculator created by Grace
Communications Foundation
(watercalculator.org).

Read Eat Less Water, by award-winning
author Florencia Ramirez. The book provides
an informative overview of the connection
between food consumption and water use
and offers tips and recipes to minimize that
impact.

Allan Frei and William Solecki Allan Frei is a professor specializing in climatology in the Department of Geography, Hunter College, City University of New York; and the CUNY Institute for Sustainable Cities.

William Solecki is founder and director emeritus of the CUNY Institute for Sustainable Cities at Hunter College.

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